Snow-avalanche Paths: Conduits from the Periglacial-Alpine to the Subalpine-Depositional Zone

Morphometric characteristics of over 250 snow-avalanche paths in northwestern Montana and southwestern Alberta differ with aspect and with position relative to the Continental Divide. Particularly notable is the difference between generally south-facing and north-facing paths. South-facing avalanche paths descend to lower elevations on gentler valleyside slopes and produce runout zones of greater extent. These same south-facing paths also are more prone to debris flows. Many avalanche paths debouche into sub-alpine lakes. Avalanche paths act as conduits that bring the hazard of the periglacial environment down to lower elevations where roads, trails, and human-use facilities are concentrated.